In the present study, the expression of three Metabolism-Related Enzymes (MRGs) that are related to glucose and pyruvate metabolism, in parallel with glucose and monocarboxylate transporter expression (HK2, MCT1, PHGDH), was studied in CTCs isolated from the peripheral blood of early stage NSCLC patients at different timepoints. Here, HK2 is linked to non-small cell lung carcinoma.